Help needed for my first solo plumbing job

[Flyfisher]

Jaqy, I've done a reasonable amount of plumbing this year, after only occasional jobs before and never with welded pipework, and I'd say you're definitely on the right lines - you certainly seem to have the right 'can-do' attitude! All the above advice is good, specially dry-fitting everything first and marking the pipe positions before welding (I got caught out on that one!).

The good news is that all the fittings are pretty cheap so if you're at all unsure then it's easy enough to make a test joint first, just to get the feel for the weld solvent and how it behaves. As noted, it does go off quickly - not too quickly that you have to rush if you know what you're doing, but fast enough that there's no second chance if you're not entirely sure. Once it 'grabs', it's pointless trying to move it any further.

As test joint is also a good idea to judge how much to apply. I was always worried about not using enough solvent. As Penners has said, twist the joint to spread the solvent evenly as you insert the pipe/fitting. But you won't get long so get it aligned quickly! I liked to see a small amount of the solvent all around the pipe after fitting to be sure I'd used enough. It's easy enough to wipe off with a damp cloth before it sets hard.

Have fun!

 

[robgil]

you need a core drill to go through the wall, can you not rotate the outlet from the trap to face the wall? also,is that copper pipe going through the wall ? is it in a sleeve?

I'm hiring a core drill tomorrow to do the job. I can rotate the outlet to face the wall but it only leaves a gap of about 10mm between it and the wall. Also, it would be impossible to get the drill in there at the right angle to go through the wall. That's why I'm bringing it all down a bit with the angles.

that trap looks a tad shallow for a belfast sink to me , are you sure it wont be a pain to drain? will it not restrict the flow and cause it to drain too slowly?

Is that likely to be a problem? It says on the packet it's for a single sink, which mine is. Why would a Belfast drain any differently to another type of sink?

Thanks for your other tips and help

If it says its for a sink it should be ok , you can test it by fitting the trap and plugging the sink , then partly fill a bucket of water (the more full the better) then pour it into the sink (with the plug in), place the bucket under the sink so that when you pull the plug the water will drain back into the bucket.
I doubt it would be too much of a pain if it did drain a little slower than the bigger traps but if you think it may be an issue its best to know before you drill a hole in your wall.

also , will the trap catch jewellery etc that might get accidental washed down the drain?

My old boss used to tell me to put as much solvent on there as possible, he liked to see it dripping off the fittings, he would tell us a tub of solvent is cheaper than going back to sort out a flooded kitchen.

 

[Andrew Bodenham]

From the photo that looks like the wrong pipe. It's marked PP - polypropylene. Pipe for solvent welding should be ABS. Either you need to get different pipe, or change over to push-fit or compression fittings. Whilst I would usually use solvent-weld fittings for tidyness and permanance there is something to be said for being able to dis-assemble a kitchen sink drain which is likely to get blocked up. Can also makes installation a bit easier, as you can rotate the assembled joints.

The trap you have pictured does not look suitable for a kitchen sink drain. I can't see how it will achieve sufficient seal depth. The normal thing for this application would be a 75mm seal tubular trap, with inlet spigots for washing machine / dishwasher if required. The thing you have looks like some sort of shower trap, but I've not come across anything quite like it before. If the trap seal isn't deep enough then the seal can self-siphon out, allowing drain smells to escape. Bottle type traps or any trap with a convoluted flow path are best avoided on kitchen sinks as they tend to clog with food waste.

This is what I'd use:

Re: the hole through the wall, all pipework should run to a light fall, say 1 in 20, so your hole should angle down a bit.

Good luck!

 

[robgil]

These traps use a 19mm seal , the recommended seal is 25mm (after evaporation and pressure fluctuations so 75mm really) so strict guidelines are attached to using them.
what are you discharging into?

this may be of help although a little more research may be required.

http://www.homebase.co.uk/wcsstore/homebase/assets/ht_work_soilandwaste.pdf

If you wanted something more in-keeping to a belfast sink you might want to look at these, they are the closest match to the old type copper traps ive found.

http://uk.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=2257567

antique ones crop up on e bay from time to time , ive had a couple from there but you might find people still producing them if you look around.

 

[Tom]

Well, I've done it!!!

It ended up a slightly longer job than anticipated (doesn't everything?! :roll: ) I had to swap the trap, as the first one I bought snagged on the brickwork when tightened up. Also, I decided to go for all push fit, which made the job a lot easier as people had said, including using a flexible pipe. However, other than that, it went very well. To keep the dust down (we're at a stage when we're trying to keep the house reasonably clean-ish) I first drilled a pilot hole from inside out, then used the core drill from the outside in. So, very little cleaning up

I still have a problem, though. I have a small leak from around the waste in the sink :roll: I think it's just going to be a case of cleaning out well around it and putting some silicone in.....hopefully! Other than that, no leaks in the new pipework The small gaps around around the pipe are stuffed with blue roll for tonight and I'll fill them properly tomorrow with lime mortar.

All in all, a great job and an even greater sense of achievment. Plus, I haven't had to pay someone else to do it

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[MdB]

 

[Flyfisher]

A neat looking job Jaqy, so I feel a bit mean pointing out that flexible pipes can be prone to 'silting' up because of the corrugations. I wouldn't bother changing it now it's in, but keep an eye out for drainage times gradually increasing. A lot depends on the sorts of stuff flushed down the plughole but I once had to fix a blocked shower waste pipe where soap and hair had built up in the corrugations of a flexible section of pipe.

From the look of the photo, if you ever do need to replace the flexible pipe, I reckon a couple of 45 degree bends and some rigid pipe - plus rotating the trap slightly - would do the job.

Now I've said all that, it'll probably be fine for evermore.

 

[Tom]

....Now I've said all that, it'll probably be fine for evermore.

Yes, that's the way things usually go, so I'm glad you've said it In fairness, we don't put much down the sink in the way of food etc., so I hope it won't be a problem. Now I've said that, it probably will be.....dammit !! :lol: :roll:

 

[FamilyWiggs]

Well done. Looks a neat job. The slight leaks from the waste may be a case of tightening the compression fitting a little. There should be a rubber seal on the underside of the "plug" in the sink. Tightened from below this should provide a perfect seal.

 

[Tom]

The water is running (well not running, it's a very small leak) from where the big nut is under the plug, on the underside of the sink, and following the thread down to the new fitting then forming drops of water. I guess there should be a seal between the nut and the underside of the sink. Is that what you're saying? If so, I wonder if the seal has gone? I hope not, because that would mean removing the waste and fitting a new one, wouldn't it? That's something I really don't want to do, as I'm worried about cracking the sink. It looks like the waste has been in there a very long time :roll: I guess I should have tested this before the sink was put in but I've never done anything like this before and no one else mentioned it :evil: If it cracks the sink, I'll have to start from scratch with another one :shock:

OK, before I get myself in a tizzy over this, I'll get a better picture of it all later and come back for some more help....if that's OK

 

[philpjuk100]

Well done!I think on old sinks that I have dismantled have been sealed with putty/plumbers mait and hessian with a lead washer underneath,I think that poly washers have replaced lead and I do not think you will damage the sink,they take a bit of "stick"I have broken damaged ones up for hard core and even with a sledge hammer its not easy! phil.

 

[Penners]

The water is running (well not running, it's a very small leak) from where the big nut is under the plug, on the underside of the sink, and following the thread down to the new fitting then forming drops of water. I guess there should be a seal between the nut and the underside of the sink.

Jaqy - Good job, well done!

To stop this leak, your (and my!) best friend is stuff called LS-X. Pop into your plumber's merchant and buy a tube. It's a clear silicone-like paste.

Undo the big nut that holds the waste in place and withdraw the waste. Put a generous coat of LS-X on the underside of the waste flange, where it lies on the hole in the sink. Now re-assemble. When you tighten up the big nut, you'll probably need someone to push a screwdriver or something into the waste from the top, to stop it revolving (the LS-X makes it more slippery). Tighten firmly, but be careful not to overdo it - this could crack the porcelain.

Thoroughly wipe away any LS-X in the sink that has oozed out from under the waste, then finely spray the edge of the LS-X with a little water. This helps it to go off.

Leave for few hours undisturbed. Your leak should be cured.

If you want to be really belt-and-braces about it, you could also buy a neoprene gasket to go between the waste flange and the sink. Take the waste into the plumber's merchant and ask for an appropriately sized one. Smear both sides of the gasket with LS-X before assembly. The only downside of this is that it tends to leave a slightly unsightly black edge visible under the edge of the waste. But it depends how important this is to you.

Good luck!

 

[robgil]

mastic might not bond to the underside of the sink if it is unglazed.
you probably have disturbed the waste fitting when connecting to it, is it centralized in the sink? if so gently nip up the nut and see if that works, if this doesnt work then i would strip it down and rebuild it using what ever sealant is on there already, if its putty id use more putty.
you dont have to seal it from the top side if it has an integral over flow, just the bottom.

 

[Penners]

mastic might not bond to the underside of the sink if it is unglazed.

I'm not sure if you're referring to my post above, Rob, but just to clarify - the LS-X goes inside the sink. The (usually) chrome flange of the waste sits on the waste hole, and the LS-X forms the seal between it and glazed part of the sink.

Jaqy, if this isn't clear tell me and I'll post a sketch.

 

[robgil]

never used lsx , i shall check it out. if the sink has an integral waste it needs sealing from the bottom, other wise if you leave a tap running and the sink overflows it will leak.

 

[Penners]

Yes, fair point.

 

[Feltwell]

LSX is wonderful stuff. I always use it on compression fittings, just to make sure.

http://www.uk-plumbing.com/fernox-lsx-external-leak-sealer-50g-p-2297.html

 

[Penners]

LSX is wonderful stuff.

Yup - the amateur plumber's best friend.

And, I suspect, the professional's too.

 

[robgil]

personally i usually dont use anything on compression fittings , if you need to use something then the joint has failed and a new olive is required.a small amount of ptfe can be added to give reassurance.
the trick is not to tighten the bejesus out of a compression fitting.

 

[Flyfisher]

the trick is not to tighten the bejesus out of a compression fitting.

I tried that trick, once, when fitting a valve to a bit of 3/4-inch black plastic pipe . . . . it came apart after about 10 minutes. :twisted:

I'm not sure of the technical term but, on refitting (with a new olive), I certainly tightened the something-or-other out of it and it hasn't failed since.